1. Field of the Invention
The present invention relates to a mechanism for locking a door of a card slot formed in an electronic device such as a digital camera. The locking mechanism unlocks the door to allow a removable card to be inserted into the card slot only when the removable card is a compatible removable card that is connectable to the electronic device.
2. Description of the Related Art
Various types of removable cards having different shape and size which are inserted into a card slot formed in an electronic device such as a digital camera (for instance, removable memory cards for digital cameras as image storing media) are available on the market. Therefore, there is the possibility that an incompatible removable card having a smaller size than a compatible removable card may be inserted into the card slot by mistake. Once such an incompatible removable card is inserted into the card slot, it is often the case that the card jams in the card slot, and in the worst cases, the card connector provided in the card slot is damaged or foreign matter is accidentally inserted into the card slot.
The primary object of the present invention is to provide a card slot door locking mechanism having a simple structure which makes it possible to prevent any incompatible removable cards or foreign matter from entering into the card slot.
To achieve the object mentioned above, according to an aspect of the present invention, a card slot door locking mechanism is provided, including a card slot into which a removable card can be inserted; a card slot door which is rotatable between a closed position, in which the card slot door shuts the card slot, and an open position, in which the card slot door opens the card slot to allow the removable card to be inserted into the card slot, the card slot door being biased to rotate in a direction towards the closed position; and a pair of door locking members positioned away from each other in a widthwise direction of the card slot. Each of the pair of door locking members locks the card slot door independent of each other when the pair of door locking members are in a free state. Both of the pair of door locking members concurrently unlock the card slot door when the pair of door locking members are concurrently pushed by the removable card when the removable card is properly inserted into the card slot.
According to the card slot door locking mechanism having such structures, since the pair of door locking members are positioned away from each other in the widthwise direction of the card slot, the removable card can be inserted into the card slot only when the pair of door locking members are concurrently pushed inward in the direction of insertion of the card into the slot, to thereby release the lock of each door locking member. Namely, even if the user tries to insert a card or a foreign matter whose width is smaller than the space between the pair of door locking members into the card slot, at least one of the door locking members remains to be locked. This prevents such an incompatible card or a foreign matter from entering into the card slot.
In an embodiment, the card slot door is formed as an elongated plate extending in the widthwise direction of the card slot, the card slot door being rotatable about a first axis extending in the widthwise direction of the card slot to be rotatable between the closed position and the open position.
In an embodiment, each of the pair of door locking members is supported on the card slot door to be rotatable about a second axis extending perpendicular to the first axis. Each of the pair of door locking members locks the card slot door by engaging an engaging portion of the each of the pair of door locking members with a corresponding stationary member which is fixedly provided within the card slot. Each of the pair of door locking members unlocks the card slot door by disengaging the engaging portion of the each of the pair of door locking members from the corresponding stationary member which is fixedly provided within the card slot.
Preferably, a biasing member is provided for each of the pair of door locking members, the biasing member biasing a corresponding one of the pair of door locking members in a direction so as to cause the engaging portion to engage with the corresponding stationary member.
In an embodiment, the biasing member is formed integral with corresponding one of the pair of door locking members. This contributes to reducing the number of elements of the card slot door locking mechanism.
In an embodiment, the card slot door is a double door having two door members positioned on the opposite sides of the card slot in the widthwise direction of the card slot, wherein each of the two door members is rotatable about an axis so as to extend substantially in the widthwise direction of the card slot when in a closed position.
In an embodiment, each of the pair of door locking members is rotatable about another axis extending parallel to the axis of the double door, wherein each of the pair of door locking members locks the card slot door by engaging an engaging portion of the each of the pair of door locking members with a corresponding one of the two door members, and each of the pair of door locking members unlocks the card slot door by disengaging the engaging portion of the each of the pair of door locking members from the corresponding one of the two door members.
Preferably, a biasing member is provided for each of the pair of door locking members, the biasing member biasing a corresponding one of the pair of door locking members in a direction so as to cause the engaging portion to engage with the corresponding one of the two door members.
Preferably, the pair of door locking members are positioned so as to be substantially symmetrical on opposite sides of a center line which extends orthogonally to the widthwise direction of the card slot and extends in a direction of insertion of the removable card, the pair of door locking members rotating in opposite rotational directions to unlock the card slot door when being concurrently pushed inward in a direction of insertion of the removable card into the card slot.
Preferably, the card slot is formed on a camera body of a digital camera, and the removable card is a memory card in which photos taken by the digital camera are stored as digital image data.
In an embodiment, the pair of door locking members are supported on the card slot door.
Preferably, each of the pair of door locking members is biased to rotate about an axis in a direction of locking the card slot door. Each of the pair of door locking members can be biased to rotate about the axis by a torsion coil spring.
In an embodiment, each of the pair of door locking members is biased to rotate about the axis by a resilient extension formed integral with the each of the pair of door locking members.
According to another aspect of the present invention, an electronic device is provided, including a card slot into which only a specific type of removable card can be inserted; a door which opens inward and closes an insertion opening of the card slot, the door being rotatable between a closed position and an open position, the door being biased to rotate in a direction towards the closed position; and a pair of door locking members positioned away from each other in a widthwise direction of the card slot, a space between the pair of door locking members being determined to correspond to a width of the specific type removable card. Each of the pair of door locking members locks the card slot door independent of respective other door locking member of the pair of door locking members when the pair of door locking members are in a free state, and both of the pair of door locking members concurrently unlock the card slot door to allow the specific type of removable card to be inserted into the card slot when the pair of door locking members are concurrently being pushed by the specific type removable card when the removable card is properly inserted into the card slot.
The present disclosure relates to subject matter contained in Japanese Patent Application No. 11-241066 (filed on Aug. 27, 1999) which is expressly incorporated herein by reference in its entirety.